An elastic-viscoplastic double-yield-surface model for coarse-grained soils considering particle breakage

The proper modelling of time-dependent behavior, such as creep and strain rate effects, of coarse-grained soils (e.g., rockfills) is important to predict the long-term deformation of high-fill projects. In this paper, the primary features of coarse-grained soil are discussed, and an elastic-viscoplastic model is proposed for simulating its time-dependent behaviors in both shear and compression. The stress-dependence of the strength, dilatancy/contractibility and creep is carefully considered based on recent experimental findings. Verifications with various experimental results demonstrate that the model is capable of predicting the creep behavior in various stress states satisfactorily.